Breast-board for underground mining.



No. 885,839. PATENTED NOV. 13, 1906. J.STOGKFLETH.

BREAST BOARD FOR UNDERGROUND MINING.

. APPLICATION FILED MAR. 22. 190B.

UNITED STATES PATENT OFFICE.

JOHN STOUKFLETH, OF NEVADA CITY, CALIFORNIA.

BREAST-BOARD FOR UNDERGROUND MINING.

Specification of Letters Patent.

Patented Nov. 13, 1906.

Application filed March 22, 1906. Serial No- 307,469.

To all whom it may concern:

Be it known that I, J OHN STOOKFLETH, a citizen of the United States, residing at Nevada City, in the county of Nevada and State of California, have invented new and useful Improvements in Breast-Boards for Underground Mining, of which the following is a specification.

My invention relates to what I call a breastboard or apparatus to retain soft ground in mining and like operations and prevent its flowing or falling into the excavation, so that the lagging may be placed and the breast of the excavation advanced.

It consists in the combination of parts and in details of construction, which will be more fullyexplained by reference to the accompanying drawings, in which Figure 1 is a longitudinal section of my breast-board. Fig. 2 is a view from the inside. Fig. 3 is a transverse section through c 4), Fig. 1. Fig. 4 isa view similar to Fig. 2, showing two bars 8 and gates 1.0. Fig. 5 is a view showing the application of my invention.

In working mining and other ground where excavations are to be made, and especially Where the ground is soft or inclined to slide or cave, it is necessary to timber up the excavation as fast as it is completed. This is effected by sets of timbers composed of two posts, a cap, and a mudsill,with brid ing-strips suported by bridge-blocks to ma e room for the agging to slip in. This lagging consists of heavy planks 3, which are driven in behind the timbers and are guided by the bridgepieces and by what are called false sets, as

at 3*, these being temporarily put in place, so

that the lagging can be driven forward and guided in the operation. The top and sides are thus protected as fast as the excavation oes on. In order to protect the front or reast of the excavation and prevent the earth from caving or moving into the excavation, breast-boards are employed. It is the object of my invention to so dispose of these breast-boards that they can be easily set and removed as the excavation advances. 4 and 5 are sections of breast-boards which are made in two parts and are hinged toether, as at 6. The ends of these boards are eveled and may be shod or otherwise formed, so that they can be introduced behind the vertical timbers, projecting far enough in each direction so t at they are supported by the timbers. By reason of the hinges these breast-boards can-be easily inserted by folding them to such an extent that one or both ends can be passed across the lagging, and the boards are afterward brought 1nto a substantially straight line and then locked in position. Thus each board being placed, a wall will be formed from the bottom to the top which holds the material of the breastin place. Then by removing the boards one at a time the material may be excavated and the breast-board advanced until another set ofrtimbers and lagging may be placed, and the breast is continually advanced in this manner as the work progresses.

In order to retain the hinge-pieces in proper alinement after they are straightened out, I employ a heavy bar or bars 8 of sufficient stiffness. One end of the bar or bars is riveted or otherwise secured to one part of the breast-board. The ,other part of the breast-board may be bent or folded independent of this free end of the bar. When the breast-board has been brought into a straight line, the breast-board W111 be substantially parallel with this bar, and by means of a slidable link or other form of latch carried bythat part of the breast-board which is free from the bar the end of the bar may be engaged with the breast-board, and the bar is thus practically fixed rigidly to both parts of the breast-b0ard, and thus maintains it in its straight position and against any tendency of the earth behind to press it inwardly.

As shown in Fig. 3, a single bar is employed, which may be made of angle, T, or other form of iron which will give rigidity,

As shown in Fig. 5, two bars are attached to the breast-boardintermediate between the top and bottom, and the free ends are brought together to form a single piece for engagement with the link or latch v9.

Boards made in this manner can thus be introduced, the ends being supported against the front ends of the laggin on each side, and one end is introduced be ind one of the lagging-planks far enough to pass the corresponding laggin on the opposite side, after which the heart would be moved back, so that both ends rest against the ends of the lagging. The whole front or breast is thus protected. In order to remove the earth or IIO 3O side of the excavation, the said boards havremovable. number as the length of the board and the Ward and replace the breast-board, commenc ing, referably, at the top and working downward with each board successively.

In my invention I have shown gates 10, which are hinged and slidable or otherwise These gates may be as many in posing den rush or cave of the material which might occur in very soft ground.

The breast-boards may have handles fixed to them at or near the center for convenience in taking down and'putting up.

Having thus described my invention, what I, claim, and desire to secure by Letters Patent, -is- 1 In mining and-like appliances, the combination with sets of timbers and suitable guide means, and lagging inserted behind the I timbers, of breast-boards having a length sufficient to extend across the lagging at each ing hinges intermediate of their length where- I by they-may be folded topass the supports,

means; for lockingthe sections in a suband s-tantiallystraight line.

2. Breast-boards for mining and like exwhereby material may be removed cavations, said boards made in a plurality of parts and hin ed together whereby they may be folded so t at the ends can be introduced behind supporting-timbers, and the board returned to a substantially straight line, means for locking the boards in such line, said means consisting of bars riveted to one section of the board, and having the free end extending beyond the hinge and over the other section, and means for securing said free end to the opposite section of the board,-

said boards having means permitting the removal of material without altering the position of the boards.

3. Breast-boards for mining and like excavations having a length sufiicient to extend across the excavation, supportinwlagging across which the ends of the boar s are extended, hinges intermediate of the ends of the boards whereby the board may be folded so that its ends will pass the supports, rigid bars fixed to one section of the board and latches by which the opposite ends may be fixed to the free ends of the boards, when the two boards are in alinement, and gates and door-openings made through the boards without disturbing the boards.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JOHN STOOKFLETH.

Witnesses:

I. C. LINDLEY, HARRY B. GRAY. 

